The present invention pertains to controlled chambers for preventing the rapid passage of air between an enclosed area having a controlled air pressure and a second area having a second air pressure. More particularly, the present invention pertains to an elevator air lock permitting free passage between an enclosed area having a first ambient air pressure and an adjacent environment having a second ambient air pressure, without the rapid passage of air therebetween.
While considerable progress has been made in the design of structures having controlled interior temperatures and air pressures, and particularly in the design of structures supported by greater-than-atmospheric interior pressures, little advancement has been achieved in containing pressurized air within the interior of the controlled structure while providing facilitated ingress and egress to and from the structure. Without such control, buildings having interior pressures differing substantially from those of the outside undergo sudden air movement between the interior environment and the outside environment whenever entry to or exit from the building is sought.
Revolving doors can provide ingress and egress for people to a building having an interior air pressure different from that of the building exterior. However, revolving doors severely limit the rate at which people can enter and leave the building. Consequently, at periods of heavy pedestrian traffic, secondary doors, frequently placed next to the revolving doors, are often used. The opening of these secondary doors destroys the air pressure control between the areas of differing pressures and results in a sudden rush of air from the area of relatively higher pressure to the area of relatively lower pressure.
Various arrangements comprising multiple sets of doors defining a pressure stabilization chamber can be used to provide air pressure control between areas of different pressures. To be effective, however, such arrangements require that at least one set of the doors be closed at all times, thus requiring that the doors first opened on one side of the chamber must be closed before the second set of doors, on the other side of the chamber, are opened, again slowing ingress and egress during times of heavy pedestrian traffic.